Exercise devices, which simulate rowing, of the type utilizing rotational inertia, e.g. from a solid or a liquid flywheel, offer a greatly improved replication of the resistance of actual rowing in comparison to rowing exercise devices which utilize hydraulic pistons, elastic cords, springs, or weights as sources of resistance. Unfortunately, although the flywheel-equipped devices provide an improved feel to the resistance, that improvement is considerably diminished by deficiencies in the design of the handles commonly used with these devices.
In a typical arrangement, the user grasps a rigid, single piece handle, which is fixed to a chain, cable, or strap at the handle's midpoint. The chain, cable or strap is passed about a sprocket or pulley, which, through a uni-directional roller clutch, is mechanically connected to the axle of the flywheel. The linear force the user applies to the handle during the power portion of the rowing stroke is thereby converted to rotational inertia of the flywheel. During the return (recovery) portion of the rowing stroke the chain slack is taken up by means of a suitable spring mechanism.
The use of a rigid, single piece handle severely restricts the physical action of the user, limiting the user's movement to an approximation of one type of rowing style, which would be similar to that used by a crewmember of a multi-person rowing shell, wherein each crew member grasps one oar with both hands.
However, proportionately few users of rowing exercise devices are competitive rowers seeking to improve their single oar technique. Most users of these devices do so for the general health benefits of the exercise these devices offer. Of those users who are competitive rowers, only a certain percentage of them would have an interest in the single oar rowing style. Many rowers use the sculling style of rowing, in which the rower uses two oars rather than one. The rigid, single-piece handle on a rowing exercise device forces these users to adopt a single oar rowing style which is of limited benefit to them. Clearly, a handle design which offers an increased range of movement, improved ergonomics, and which also allows the user to replicate single and double oar rowing styles, would be of obvious benefit to both the average user and the competitive rower.
There have been limited attempts by others to design an improved handle for flywheel type rowing exercisers. For example: U.S. Pat. Nos. 4,743,011 issued May 10, 1988 in the name of Coffey; and 7,270,630 issued Sep. 18, 2007 in the name of Patterson disclose conventional rowing machines attempting to duplicate sculling-style rowing.
U.S. Pat. No. 4,743,011 issued in 1988 to Calvin Coffey discloses a design of flywheel based rowing exercise device, which provides a somewhat accurate replication of a double oar rowing action by fitting the device with oar handles and shafts, oar locks, and mechanical means to convert the arcuate movement of the oars to rotational movement of the flywheel. However, the design is not intended as a retrofit of currently available rowing exercise devices, since the Coffey device requires major mechanical changes and reconfiguration of components, e.g. repositioning the flywheel from a forward to a rearward location.
U.S. Pat. No. 7,270,630 issued in 2007 to Paul Patterson, as part of a design for a rowing exercise device, discloses a handle design, which allows a greater range of movement than offered by the standard rigid single piece handle. However, due to the forward space requirements of the handle design, it also cannot be easily adapted to currently available rowing exercise devices.
The embodiments of the present invention enable replication of single and double oar rowing styles on a flywheel-type rowing device. Successful replication of the stroke geometry of actual rowing requires that the characteristics of that geometry be understood.
FIG. 1 illustrates a conventional oar/oarlock arrangement in which an oar 200 with an oar handgrip 201 is mounted in an oarlock 202 of a boat 203. Pulling on the oar handgrip 201 will cause the handgrip 201 to move through an arc, the radius of that arc being defined by the distance between the handgrip 201 and the oarlock 202.
At any moment in the progression of the rowing stroke, the rower can rotate the handgrip in any direction about the z-axis. Also, at any moment in the progression of the stroke, the rower can by raising or lowering the handgrip 201, cause the handgrip 201 to rotate in any direction about the x-axis. The magnitude and direction of these rower controller rotations about the z and x axes are independent of each other and are independent of the position of the handgrips in space with respect to the progression of the rowing stroke.
The magnitude and direction of rotation of the handgrip 201 about the third axis, i.e. the vertical y-axis, is entirely dependent on the stage of progression of the rowing stroke. Unlike rotation of the handgrip 201 about the z and x axes, the rotation of the handgrip 201 about the y-axis is fixed and immutable at any moment in the progression of the rowing stroke. To put it another way, if the rower were to stop at any stage in the progression of the rowing stroke, the rower would be able to rotate the handgrip 201 about the z and x axes, but would be unable to rotate the handgrip about the vertical y-axis. Rotation about the y-axis can only be effected by stroke progression.
It follows from these observations of the geometry of actual rowing, that replication of rowing, if it is to achieve satisfactorily realistic results, must retain independence of handgrip rotation about the z and x axes throughout the rowing stroke, and ensure that handgrip rotation about the vertical y-axis remains directly dependent on the horizontal progression of the rowing stroke.
Accordingly, using the geometry of actual rowing as a guide, any embodiment enabling replication of rowing must, whether replicating the “standard” style of rowing or the crossover style of rowing, ensure that the above-identified angular progression about the y-axis is a smooth, aberration free change directly proportional to the progression of the rowing stroke.
Although rower controlled handgrip rotation about the z-axis is a characteristic of actual rowing, in tests, its exclusion is not experienced as a defect. If desired however, handgrip rotation about the z-axis could easily be added to any of the disclosed embodiments.
Rower controlled handgrip rotation about the x-axis is restricted in actual rowing. In all of the disclosed embodiments, handgrip rotation about the x-axis is unrestricted, which enables the user to adopt hand positions unrelated to actual rowing, thereby greatly increasing the versatility of the rowing exercise device, but without affecting the fidelity of rowing replication, if the user chooses to exercise in various styles.
In actual rowing, at the beginning of the stroke, the handgrips of the oars are at a certain distance apart. As the stroke progresses, each of the handgrips move through an arc, reducing that initial separation, and then moving apart again as the handgrips continue to follow that arc to the end of the stroke. The functional characteristics of the disclosed embodiments do not include the handgrip separation at the beginning of the stroke. Like the lack of rotation about the z-axis of the handgrips, the lack of hand separation at the beginning of the stroke is not experienced as a defect, because it feels completely natural and ergonomically correct.
It was also determined that the required arc of movement to approximate the arc sweep of actual oars, was a natural outcome of the user's body mechanics and does not need to be mechanically dictated. Accordingly, two arms hinged at the front with handgrips mounted at a fixed angle on the ends of those arms would still produce a smooth angular progression of the handgrips as the handgrips followed the natural arc defined by the user's body mechanics, and as the hinged arms of the device spread during progression of the stroke.
An object of the present invention is to provide an accurate replication of the rowing motion, by providing a rowing handle, which is more readily adaptable to currently available rowing exercise devices that have limited space requirements during use.
Another object of the present invention is to overcome the shortcomings of the prior art by enabling the user a greater range of movement than afforded by a single piece handle. The present invention enables the geometry of the user's movements to be ergonomically correct, following natural body mechanics and thus reducing the possibility of strain injury. Moreover, the present invention enables the user to replicate the physical movement of single and double oar rowing styles, or if the user wishes, to adopt stroke geometries unrelated to actual rowing, thereby bringing various muscle groups into play and thus broadening the usefulness and appeal of rowing exercise devices.